D2/1.2379 cold work tool steel is chrome-molybdenum-vanadium steel with big hardenability for hardening in oil and in air, especially high resistance to the wear (higher than by 1.2080), good cutting power, very good firmness in the pressure, lower toughness (but higher than by 1.2080). This steel shows good dimensional stability at the heat treatment, suitable for hardening to the secondary hardness (the possibility of nitriding). Further the steel is very difficult to sharpen, it works at the heat with difficulties and has a rather difficult workability in the annealed state. D2/1.2379 is suitable for making tools for cold cutting, i.e. all kinds of tools with the long durability for cutting on presses and punching of materials of smaller thicknesses and materials of high hardness (especially difficult-shape tools for cutting, e.g. transformer metal sheets and metal sheets from stainless steels), knives for plate shears for the sheet and strip steel up to thickness of 10 mm of sheared material, knives for wire cutting etc. Tools for mechanical working such as e.g. smaller girders and tools for drawing, all kinds of tools for transformation and punching of materials. Further the steel is suitable for simple and symmetric tools for pressing and pushing, tools for thread rolling, plain and profile rolls, swages and also for cold work. Cutting tools such as broaching thorns, profile knives and difficult-shape milling machines for lower cutting speeds and for treatment of nonmetallic abrasive materials. Further the steel is applied in the production of highly stressed molds and their components for working of plastic and powder substances, glass, porcelain and ceramic materials. By tools for crushing and grinding it is used for hammers of crushers and jaws for mild grinding and crushing.